Thread-controlling mechanism for sewing machines



- Feb. 5 1924.. 11,482,671

E. B. ALLEN THREAD CONTROLLING MECHANISM FOR SEWING MACHINES Filed Dec. 21, 1921 WITNESSES:

INVENTOR TTORNEY Patented Feb. 5, 19.24.

EDWARD B. ALLEN, OF NEWTOWN, CONNECTICUT, ASSIGNOR TO THE SINGER MANU- FACTURING COMEANY, F ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY.

THREAD-CONTROLLING MECHANISM FOR SEWING MACHINES.

Application filed December 21, 1921.

To all whom it may concern:

Be it known that I, EDWARD B. ALIEN, a citizen of the United States, residing at Newtown, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Thread- Controlling Mechanisms for Sewing Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

In certain types of sewing machines such, for example, asbuttonhole sewing machines the stitch-forming mechanism of which embodies a laterally jogging needle which in its successive thrusts cooperates alternately with loop-takers of different character, such as threaded and non-threaded loopers, it is desirable for the best control of the needlethread that the take-up action should be different in degree in successive reciprocations of the needle.

To this end, in the machine of my Patent No. 1,339,733, of May 11, 1920, use is made of a take-up cam rotating at half the speed of the needle-bar driving shaft, such cam being adapted for different action upon the thread at the opposite sides of a diameter.

An object of the present invention is to provide a simplified form of take-up having a variable action adapting it for use with stitch-forming mechanism embodying a reciprocating and laterally jogging needle.

Another object of the invention is to provide a sewing machine with a. plurality of independent take-up devices which may be used selectively for the control of the needlethread in effecting modifications in the character of the seam, such as a change from a buttonhole having a pyramid purl to one having a flat purl.

In carrying the invention into elfect, use is made of two movable thread-engaging devices, one of which devices is operated at halfthe frequency ofthe other device and modifies the action of the latter on the thread. In the particular embodiment of the invention chosen for the purposes of the present disclosure, the hollow needle-bar of a machine, such as disclosed in my said patent, constitutes one of the thread-engaging devices and a horizontal bar disposed closely in rear of the needle-bar and connected to the usual needle-jogging mechanism constitutes the second thread-engaging device 'tation.

Serial No. 523,843.

which reciprocates at half the frequency of the needle-bar. The degree of take-up action of the needle-bar will thus depend upon the position or motion of the second threadengaging device which is alternately lifted and lowered at half the frequency of reciprocation of the needle-bar and hence alternately augments and reduces the take-up action of the needle-bar, whereby the takeup action is accommodated to the diiferent conditions involved in the employment of alternately acting loop-taking devices of different character when combined with a reciprocating and laterally jogging needle.

This take-up may be incorporated in my prior machine independently of or in addition to the usual rotary take-up, in which latter case a plurality of independent takeup devices is afforded, either of which may be selected and threaded up for use by the operator, as may appear best suited to the production of t e particular seam or type of buttonhole to be stitched.

In the accompanying drawings, Fig. 1 is a side elevation, partly in section, of a buttonhole sewing machine embodying the invention. Figs. 2 and 3 are detail views of the needle-thread tension spring and as sociated parts. Fig. 4 is a detail plan view of the actuating lever for the needle jogging mechanism. Figs. 5 and 6 are side views illustrating the variation in the take-up action in successive reciprocations of the needle and Fig. 7 is a front view of the take- .up elements.

For the purposes of the present disclosure the invention is embodied in a buttonhole sewing machine having the constructive features disclosed in my Patent No. 1,372,472 of March 22, 1921, and including stitchforming mechanism such as" disclosed in the Allen et al. Patent No. 1,372,473, of March 22,1921.

The machine frame comprises the usual bed 1, standard 2 and bracket-arm 3 terminating in the head 4 in which the needlebar 5 is journaled for reciprocation and ro- The needle-bar 5 carries at its lower end the usual yoke 6 for the horizontal pin 7 on which the carrier 8 for the needle 9 is mounted for lateral jogging movements; such movements being imparted to the needle-carrier 8 by means of the usual operative connections with the vertical needlejogging slide-rod 10 which is journaled in the head 4 in parallelism with the needle-bar as set forth in my said Patent No. 1,339,733.

The needle-jogging slide-rod 10 is reciprocated in the usual manner by means of the cam 11 on the vertical shaft 12 which interconnects the usual needle-bar operating shaft 13 and loop-taker operating shaft 14. The cam-shaft 12 runs at half the speed of the needle-bar operating shaft 13 and imparts vibratory motion to the lever 15 which transmits such motion through the link 16, bellcrank-lever 17 and link 18 to the needle-jogging slide-rod 10. The rod 10 is thus reciprocated at half the frequency of the needle-bar and operates to jog the needle laterally for the usual alternate slit-stitch and depth-stitch thrusts.

The needle 9 cooperates with the usual loop-taker mechanism such as disclosed in my said patent and comprising the threaded and non-threaded loopers, the latter of which is shown at 20. These loopers are mounted on the oscillating looper-carrier 21 and cooperate alternately with the needle 9 and the loop-detainers 22 and 9.3.

In lieu of the usual take-up cam 24:, such as shown in my Patent No. 1,339,733, good results may be had by using a simplified takeup constructed, in the embodiment of the invention illustrated, by mounting a threadengaging member 25 on the needle-jogging slide-rod 10 and arranging such member to engage the needle-thread in rear of the upper end-portion of the usual hollow needlebar through which the thread extends to the needle. The thread-engaging member 25 may be made up by bending a wire so that it will extend rearwardly, as at 26, from the top of the bar 10, thence transversely of the bracket-arm 3 across the lead of the needlethread, Fig. 7, and thence downwardly as at 27, to form a hook serving to prevent the escape of the needle-thread over the free end of the member 25.

The needle-thread is led through the usual tension device 28 and through the aperture 29 into the housing 30 for the take-up cam 24. ithin the housing 30 the needle-thread is passed through the eye 31 of the slack thread controlling spring and thence out through the aperture 32. The thread then passes through the guide-post 33, under the take-up member 25 and into the hollow needle-bar. When, as described, the needlethread is not passed through the apertures in the arms 34, the rotary take-up cam 24 is functionless. In the present machine such cam is, however, available and may be used in lieu of the member 25 by merely running the needle'thread through the arms 34 and cast-off plate 35 in the customary manner, in which case the bar 25 may be turned to one side so as not to engage the thread.

In the claims, the needle-bar and threadengaging element 25 are characterized as reciprocating thread-engaging elements. It is to be understood that the term reciproeating is used in its broadest sense meaning to-and-fro moving and is not to be understood as limiting the motion of the thread-engaging elements to rectilinear paths.

It is further to be understood that either the rotary or reciprocatory take-up may be successfully used in combination with stitchforming mechanism of the type under discussion. Experiments appear to indicate, however, that under certain conditions and when sewing certain classes of work the reciprocating take-up is preferable, while under other conditions the use of the rotary take-up enables the operator to more nearly effect the desired result.

Having thus set forth the nature of the invention, what I claim herein is- 1. A sewing machine having a needle-bar actuated main take-up member, and an auxiliary take-up member actuated independently of the needle-bar and operating at half the frequency of the main take-up member.

2. A sewing machine having a main takeup member and an auxiliary take-up member having a smaller take-up action than the main take-up member and operating at a lower frequency than the latter.

3. A sewing machine having a main takeup member and an auxiliary take-up member having a smaller take-up action than the main take-up member and operating at half the frequency of the latter.

4. Sewing machine take-up mechanism comprisinga reciprocating needle-bar having take-up thread-engaging means, a thread-guide adjacent said means, and means for moving said thread-guide to and fro in the direction of reciprocation of said needle-bar at half the frequency ofreciprocation of the latter.

5. In a sewing machine having a reciprocating and laterally jogging needle coo-perating alternately with loop-takers of different character, a needle-thread take-up comprising two movable thread-engaging members, and means for reciprocating said members, one at half the frequency of the other.

6. In a sewing machine, the combination with stitchforming mechanism includin a reciprocating and laterally jogging nee le, of a variable needle-thread take-up, the action of which is cont-rolled by the needlejogging mechanism. 7

7. In a sewing machine, in combination, stitch-forming mechanism including. a reciprocating and laterally jogging needle, a first thread-engaging device reciprocating in time with said needle, and a second thread-engaging device reciprocating adjacent the first thread-engaging device in time glith the lateral jogging motion of the neee. 8. In a sewing machine having a reciprocating and laterally jogging needle 00- 5 operating alternately With loop-takers of different character, a take-up comprising parallel slidably mounted bars, means on said bars for engaging the needle-thread, and means for reciprocating said bars, at different frequencies. 10

In testimony whereof, I have signed my name tothis specification.

EDWARD B. ALLEN. 

